An opening and closing apparatus of an opening and closing member generally includes a pulley and a transmission belt engaged at the pulley. The transmission belt is linked to the opening and closing member. The aforementioned apparatus opens and closes the opening and closing member by driving the pulley to rotate by an electric drive source to move the transmission belt.
As illustrated in FIG. 6, an opening and closing apparatus disclosed in Patent document 1, for example, includes a support member 101 made of resin. The support member 101 includes a pair of support wall portions 101a and 101b arranged side by side in a height direction of a vehicle to be integrally provided. In a state where a pulley 102 is disposed between the support wall portions 101a and 101b, axially opposed end portions of a support pin 104 of the pulley 102 are supported at the support wall portions 101a and 101b, respectively. A belt 103 is engaged at the pulley 102. Each of the support wall portions 101a and 101b includes an opening portion which opens in a radial direction from an axis of the pulley 102 towards a contact portion between the pulley 102 and the belt 103. Each of the support wall portions 101a and 101b is formed in a substantially U-shape, i.e., in a non-annular form. The axially opposed end portions of the support pin 104 are press-fitted to the respective opening portions of the support wall portions 101a and 101b so that the support pin 104 is supported at the support wall portions 101a and 101b. Accordingly, the pulley 102 is supported to rotate around the support pin 104.